BUDAPEST, Hungary -- Migrants caught cutting through the fence being built to stop them on the border with Serbia should be "punished in an exemplary manner," including prison sentences, Hungary's governing Fidesz party said Friday.

State media reported 18 migrants had been caught overnight after cutting through the fence near the Hungarian village of Asotthalom where construction began this week.

"It is not enough that illegal immigrants are crossing the country's border unlawfully, on top of it all they are damaging property of the Hungarian state," Fidesz parliamentary group leader Antal Rogan said in a statement.

Over 110,000 migrants have arrived in Hungary this year, nearly all walking across the southern border with Serbia. Prime Minister Viktor Orban said a four-metre high fence being built there by the Hungarian army will be finished by Aug. 31.

So far, neither the first sections of the fence nor the presence of the soldiers seems to have discouraged the migrants, most of whom have come from Syria, Afghanistan, Iraq and other war-torn regions in recent months.

The daily number of migrants caught by police has been rising steadily, rarely falling below 1,500 a day since mid-July. Around 300 a day were being caught in April and 400 daily in May.

Most of the migrants request asylum in Hungary but attempt to continue toward richer countries like Germany or the Netherlands further west in the European Union before their claims are settled.

Rogan said Fidesz would seek to make cutting the fence a crime punishable by jail as soon as parliament returns in September from the summer break.